hyperhive/nix/module-eval/hive-tls.nix

# `checks.module-eval-hive-tls` — see ./lib.nix for the shared rationale (why
# this suite exists, naming convention, "evaluates not executes").
#
# The swarm-services leaf's renewal: a timer that really re-runs the
# issuance, at a threshold read off the store role's lifetime.
{
  pkgs,
  lib,
  self,
  nixosSystem,
}:
let
  inherit
    (import ./lib.nix {
      inherit
        pkgs
        lib
        self
        nixosSystem
        ;
    })
    hive
    runGroup
    ;

  # Every service on one host, so the store's granting unit renders the role
  # this leaf is issued through.
  allLocal = hive {
    deploy.singleHostSwarm = true;
  };

  # The same host with the role's lifetime moved, so a threshold that is a
  # number of its own shows up as one that did not move with it.
  shortTtl = hive {
    deploy.singleHostSwarm = true;
    deploy.bao.servicesPkiLeafTtlHours = 48;
  };

  units = allLocal.systemd.services;
  boot = units.swarm-services-cert;
  timer = allLocal.systemd.timers.swarm-services-cert-renew;

  # What the timer starts, read off the timer rather than assumed from its
  # name: a timer's `Unit=` defaults to its own name, and pointing it at the
  # boot unit is exactly the regression the cases below exist for.
  triggeredName = lib.removeSuffix ".service" (
    timer.timerConfig.Unit or "swarm-services-cert-renew.service"
  );
  triggered = units.${triggeredName};

  remainsAfterExit = u: u.serviceConfig.RemainAfterExit or false;

  renewAt = hours: "renewat=$(( ${toString hours} * 3600 / 2 ))";

  cases = [
    {
      # Control: the boot issuance is the unit a timer cannot re-run. Were it
      # not `RemainAfterExit`, the case after next would pass vacuously.
      name = "the boot issuance renders, and stays active after it exits";
      ok = lib.hasInfix "pki/issue/swarm-services" boot.script && remainsAfterExit boot;
    }
    {
      name = "a timer for the services leaf is enabled and fires daily";
      ok =
        lib.elem "timers.target" timer.wantedBy
        && timer.timerConfig.OnCalendar == "daily"
        && timer.timerConfig.Persistent;
    }
    {
      # Starting an active unit is a no-op, so a timer aimed at a
      # `RemainAfterExit` unit fires on schedule and renews nothing.
      name = "the timer starts a unit that re-runs the issuance and does not stay active";
      ok =
        units ? ${triggeredName}
        && !(remainsAfterExit triggered)
        && triggered.script == boot.script
        # The whole set, `PATH` included: an environment copied off the
        # boot unit's merged options renders a second `PATH` and fails.
        && triggered.environment == boot.environment;
    }
    {
      # A restart of anything the gateway's cert import `Requires=` takes
      # nginx down with it, so the renewal must be something nothing else
      # depends on, and must run behind the boot issuance.
      name = "nothing requires or waits on the renewal, and it runs after the boot issuance";
      ok =
        (triggered.requiredBy or [ ]) == [ ]
        && (triggered.wantedBy or [ ]) == [ ]
        && (triggered.before or [ ]) == [ ]
        && lib.elem "swarm-services-cert.service" triggered.after
        && !(lib.any (u: lib.elem "${triggeredName}.service" ((u.requires or [ ]) ++ (u.after or [ ]))) (
          lib.attrValues (removeAttrs units [ triggeredName ])
        ));
    }
    {
      # Moved with the role, in both places: the threshold is half of what the
      # store grants, and the store grants what the option says.
      name = "the leaf is renewed at half the role's lifetime, read from the option";
      ok =
        lib.hasInfix (renewAt 720) boot.script
        && lib.hasInfix (renewAt 48) shortTtl.systemd.services.swarm-services-cert.script
        && lib.hasInfix ''-in "$svcleaf" -noout -checkend "$renewat"'' boot.script
        && lib.hasInfix "max_ttl=48h" shortTtl.systemd.services.swarm-bao-controller-policy.script;
    }
    {
      # The store replaces its root once it has less than one leaf lifetime
      # left, and the hive asks for a fresh leaf, with the new root, at that
      # same threshold. A number of its own here keeps a leaf whose root the
      # store has already replaced.
      name = "the services root is re-checked at the store's own replacement threshold";
      ok =
        let
          shortBoot = shortTtl.systemd.services.swarm-services-cert.script;
          shortStore = shortTtl.systemd.services.swarm-bao-controller-policy.script;
        in
        lib.hasInfix ''-in "$svcroot" -noout -checkend ${toString (720 * 3600)} '' boot.script
        && lib.hasInfix ''-in "$svcroot" -noout -checkend ${toString (48 * 3600)} '' shortBoot
        && lib.hasInfix "-checkend ${toString (48 * 3600)} <<<\"$root_ca\"" shortStore;
    }
  ];
in
runGroup "hive-tls" cases